The Sugar Engineers

Turbine Steam Consumption Calculations

The usual way of representing the steam consumption of a turbine is the willans line, for example...

Often, a willans line for a specific turbine is not available, and one only has has incomplete information about an installed steam turbine; namely the rated power and (perhaps a guesstimate) the isentropic efficency or specific steam consumption at full load. But what you need and don't have is the steam consumption at the turbine operating load.

Background Information

Isentropic efficiency η by definition is given by

η = (hHP - hLP) / (hHP - hLPisen)

where

hHP is the specific enthalpy of the steam at the turbine inlet

hLP is the specific enthalpy of the steam at the turbine exhaust

hLPisen is the specific enthalpy of the steam at turbine exhaust pressure but after isentropic expansion from the HP conditions